Heretofore in the auto and other industries, plastic parts have been chrome plated wherein considerable quantity of plastic parts are rejected for improper finish or improper plating or from other defects in the final product such as would render plastic material, usually acrylonitrile-butadiene-styrene polymer, hereafter referred to as A.B.S., though not limited thereto, for scrap and waste. Plastic chrome plated rejects are in abundance in very large quantities at 14 cents per pound for regrinding whereas prime plastic material has a value of one dollar per pound, approximately. Heretofore in forming plastic articles, there are impurities within the plastic material. Such impurities may show up in the final injection molded plastic product or other plastic product as irregular surfaces. Ferrous, copper and chrome dust powder often damages the sprue and mold in an injection molding machine, often destroying the high gloss finish required on chrome parts of new products. These chrome plated products are often rejected with great loss of profits, plus injury to equipment, wherein the rejected plastic product must be reground for use to recover some of the loss. Various efforts have been made for removing principally the chrome from the reground plastic product, or other metal materals such as copper, nickel and certain ferrous powders.
Various efforts have been made to try to purify the scrap chrome plated plastic, however it appears that these efforts have been unsuccessful, since no effective means has been developed for separating substantially all of the chrome and other metals from the ground up reject plastic parts.
Heretofore electromagnetic systems have been tried, however, essentially these have been ineffective due to the reluctance of some of these materials such as chrome, nickel, copper to adhere to magnets. Efforts have been made to provide a manual type of magnetic separator wherein before ground plastic pellets are fed into a molding machine, or into extruders, the material is passed over a series of tubes containing magnets. After some of the metal material has adhered to the tubes, the tubes must be moved from the machine and manually wiped off before they can be used again often resulting in a shut-down of the plastic equipment resulting in an inefficient separation of only some of the metal materials.
Since the plastic material before melting and injection into a plastic mold is of a relatively fine powder of approximately 30 mesh, for illustration, initial efforts to magnetically separate such metal materials from the plastic such as chrome, copper, nickel and iron, have been ineffective due to the continuous flow of the greater quantity of plastic materials through the separator as the material passes into a conventional extruder, or other device for liquifying the plastic material prior to molding.